The present invention relates to a type of bed mattress and a method of constructing same, and in particular to a mattress which allows an end user to access the interior of the mattress.
The conventional inner construction of present bed mattresses includes an inner coil spring unit surrounded on the top and bottom by padding which provides a barrier and cushion against the metal springs. In better quality mattresses a wire grid is further provided as a barrier between the padding and the spring unit. The padding is then padded on its top and bottom by layers of foam, cotton, and other materials. The typical outer construction of a mattress includes a top and bottom cover, and a border which surrounds the four sides or perimeter of the spring unit. The covers and border are usually quilted fabric available in a variety of colors and print patterns, thus providing the initial aesthetic appeal to the customer.
A flange formed by a strip of strong fabric is attached to the boundaries or peripheries of the top and bottom covers prior to the final assembly of the mattress. The top and bottom flanges extend over the side edges of the spring unit and are anchored to the springs using metal rings, commonly referred to as "hog rings". The flanges fix the padded layers in place on the top and bottom of the spring unit, so that during prolonged use the various layers are not dislodged. The flanges also serve to resist the tensile forces around the perimeter of the bed resulting from a body resting on top of the mattress.
A specialized tape edge machine, mounted on a special table, is used to attach the border to the top and bottom covers after the flanges of the covers have been attached to the spring unit. Wads of cotton material are often inserted just prior to the covers' attachment in order to round and pad the corners of the mattress. Also, stiffening members may be affixed to upper and lower border rods along the mattress sides prior to final assembly, for people who sit on the edge of the bed and require extra support therein.
In the final assembly of the mattress, a decorative tape is folded over the raw edges of the cover, flange, and border materials by an operator. The operator must manually position the tape over the raw edges while walking backward, as the machine moves around the mattress and stitches the tape to form a welt around the mattress perimeter. This is done for the top cover attachment to the border, and also for the bottom cover attachment to the border. The tape edge machine and its required components are quite costly, and a highly skilled operator is required to produce quality mattresses.
There are some fold-away mattresses for sofa beds or Murphy (wall) beds which use a "bucket" construction. In this construction only a top cover has a flange which is anchored to an inner spring unit. A bottom cover and border are sewn together and the inner spring unit placed within. The tape edge machine is then used to attach the top cover to the top of the border. Even less expensive fold-away mattresses may use a foam unit within the bucket construction and completely omit the use of flanges. However, none of these fold-away mattresses allow access to the interior after final assembly of the mattress.
The flange construction also does not apply to water beds, where an outer cover may be separately constructed and then attached over the water mattress without the special machinery and technique described above. This is because the typical water bed mattress has a foam border construction which provides the functions of fixation and force resistance that flanges provide. That is, water beds do not require flanges and therefore do not require the special machinery or skilled labor.
There also are mattresses presently available which allow the top cover to be reversed, although this still does not provide access to the interior. Velcro or other such means is provided on the top of an upper mattress cover, over which a separable panel is placed. This panel may be padded or quilted, or a thick wool material may be attached on one side. This reversible construction is an additional feature that is independent of the attachment of the mattress outer covers during final assembly.
Most of the components for bed mattresses, such as the quilted material, foam, padded layers, and spring units are readily available from several sources. In fact, many mattress manufacturers simply obtain these components and perform only the flange and border attaching procedures on site. That is, the manufacturers provide only the final assembly of the mattresses.
However, because of limited storage space and for inventory control, only certain combinations of springs/padding/foam/quilted covers are usually maintained by each manufacturer. These are usually stored in intermediate stages of assembly, so that customization of a mattress--i.e., using a different padding or quilted cover requires a lengthy wait to fulfill the custom order. Thus, consumers are quite limited in the immediate selection afforded by the present mattress manufacturers and retailers, unless a great amount of time and money is willing to be spent to obtain the ideal mattress construction.
Not only is the customer limited in his choice from what is available from a particular dealer, as either a custom order or from stock, the customer must take the salesperson's word that the interior construction of the mattress the customer takes home is the same as the mattress displayed in the store. That is because the inner construction of the mattress is obscured once final assembly of the border to the top and bottom covers is completed, so that the consumer is blind as to the actual construction of both the store's displayed mattresses and his own mattress once it is at his home. While the outer covers are easily verified, at least for the color/pattern and quilting style, the true worth--and cost--of the mattress is in the padding and spring unit construction which are the most important elements for restful sleep and for durability.
A further problem with present mattresses is that any moisture absorbed by the mattress results in time spent drying the mattress, as well as possible mildew or other lingering odors. The moisture may be from a spilled glass of water, or a buildup of normal bodily secretions over time. Two ways presently used to avoid or reduce wetness and odor are the use of waterproof sheets and the presence of vent holes on the sides of the mattress. The sheets prevent moisture from being absorbed by the mattress, but only if positioned over all possible areas of wetness. The vent holes allow some ventilation of the interior of the mattress to speed drying somewhat, but may not completely prevent odors from resulting.